Is it obligatory for me to continue giving from my salary to my parents and siblings, given my desire to build my own house and that my parents are employed with a good salary, or am I entitled to set aside a portion of my salary to secure my future?

You are not obliged to give your father anything from your wealth if he is not in need of it. He is also not permitted to take what you need or to cause you hardship. Be wise and gentle with your father, and continue to show him righteousness and kindness as much as you can, for showing righteousness to parents is among the best acts of drawing near to Allah.